Feeling Trapped in Adoptive Placement

Hey Guys. My wife and I have 2 biological children(10/6 boys) and we recently started a foster to adopt situation with a 9 year old boy. He has been in our house full-time for 2 months now and I just cant stand it anymore. I wanted to bond with this kid so badly, but I cant stop trending the other direction. When he first got in our home I enjoyed spending time with him, but over the course of the last two month I have grown to hate our time together. I am constantly annoyed by his presence and just want him to go away. I feel like he is a bad fit for our family and he is bringing out the worst in my bio kids (aggression, violence, misc bad behavior). My wife on the other hand thinks he is great. We are in a transition and all of the behavior will balance out given enough time....she may be right...but I don't see it. I admitted to her that I was having doubt about us being an ideal placement and discussed what "pulling the plug" on the placement would look like. Through the torrent of tears that followed she begged me to allow her to adopt and then we could get a divorce. Said she couldn't live with me or live in our home without the adoptive child and that I was a heartless monster for not loving this kid. I am trapped. I love my wife and do not want a divorce. I went along with the adoption up until now out of love for her, it was never really my choice. I did not get to pick the gender, I did not get to pick the age, I did not get to pick the child, the only choice I get is wither get to keep my wife and bio kids. Any encouragement or advice would be greatly appreciated. Thanks,